Holding my 3-speed in 3rd gear or pops out

[dwcsr]

Originally Posted by Harveybacon

it's a 3-on-the-tree Muncie 219 or 319 from what I remember. 4-bolt on side.

SM 319 is an over drive 3 speed tranny, You should have and SM 318. Popping out of third is most likely cuased by the 2nd/third shift fork being worn or the 2nd third syncro slider being bad or the input shaft bearing being bad. Could be all three. But it does have to come apart to find out.

$400 should get you a complete rebuild provided the broken parts are available and not major components.